The reconstruction or cosmetic variation of a breast, such as often performed following mastectomy, has become an increasingly frequent surgical procedure. The development and use of silicone-gel and silicon-filled implants have contributed to the popularity of this procedure. Recent concern over the effects of the filler of these implants, e.g. silicone-gel, on the health of women has lead to a decrease in their use.
Saline has been suggested as a filler for breast implants. Saline is considered biocompatible. However, when used in breast implant, saline does not provide the density or feel of natural breast tissue.
Therefore, it is desirable to provide a filler material for an implant which simulates or duplicates the characteristics of a natural breast. Further, it is desirable to provide a material that does not have an adverse effect on the human body containing the implants.
WO 90/04971, with Pennel et al. as inventors and corresponding to U.S. Pat. No. 4,983,585, relates to improved viscoelastic fluids or gels for use in surgery and other therapies. The viscoelastic fluid or gel has as its principal ingredients polyethyleneoxide in a physiological balanced salt solution. The viscoelastic fluids or gels may include a viscosity enhancer or stabilizer. The viscosity enhancers or stabilizers include hydroxypropyl methylcellulose, carboxymethyl cellulose, hydroxypropyl cellulose, hydroxyethyl cellulose, methyl cellulose or mixtures thereof, polyvinyl pyrrolidone, or polyvinyl alcohol. Polyethyleneoxide is an essential ingredient in the viscoelastic fluids or gels. Pennel et al. contains no suggestion that useful fluids or gels may be prepared without polyethyleneoxide.
U.S. Pat. No. 4,772,284 relates to a breast prosthesis with improved bio-compatibility and methods of making the same. The breast implant is a single lumen implantable and biocompatible breast implant composed of an outer membrane of silastic, medical grade silicone, and an inner material selected from the group consisting of purified reconstructive collagen gel and a purified gel of poly-alpha amino homopolymers or random copolymers having a molecular weight of from 5,000 to 400,000.
U.S. Pat. No. 4,787,905 relates to gel for breast prostheses. The gel is a mixture of hydroxy-terminated polybutadiene resin, diundecylphthalate, polymethylenepolyphenyl isocyanate, and dibutyltin dilaurate catalyst, wherein the mixture is cured to form the gel.
U.S. Pat. No. 4,790,848 relates to a breast implant with multiple lumens. The implant comprises an inner lumen of substantially spherical shape. The inner lumen is unattached, or free-floating. The lumens are filled with silicone gel or similar fluid material.
U.S. Pat. No. 4,995,882 relates to a radiolucent breast implant. The radiolucent breast implant is composed of a silicone envelope filled with any biocompatible triglyceride such as peanut oil or sunflower oil or any other material having an effective atomic number of 5.9, which is the effective atomic number of fat. This breast implant is radiolucent in that it duplicates the photo-electric interference of fat which is the major effect producing subject at low radiation levels as used in mammography.